An Inertial Navigation System for a Mobile Robot

A low-cost, solid-state inertial navigation system for robotics applications is described. Error models for the inertial sensors are generated and included in aifixtended Iialmang(lter (EKF) for estimating the position and orienta- lion of a moving robot vehicle. A solid-state gyroscope and an accelerometer have been evaluated. \\'itliout error compensa- lion, the error in orientation is between 5--1f1~/111in but can be improved at least by a factor of 5 if an adequate error model is supplied. Similar error models have been developed for each itxis of a solid-state triaxial accelerometer. Linear position esti- mation with accelerometers and tilt sensors is more susceptible to errors due to the double integration process involved in esti- mating position. \Vith tlie system described here, the position drift rate is 1- cm/sm, depending on the frequency of acceler- modelling of error sources, low cost inertial sensing systems can provide valuable position information. k